KR20030029963A - Expandable polyester resin composition - Google Patents

Abstract

(A) 0 to 50 parts by weight of an acrylic ester monomer in the presence of a latex of a polymer having a specific viscosity of 0.7 to 1.9 obtained by polymerization of (B) 50 to 100 parts by weight of (B) a methyl methacrylate monomer. A foamable polyester resin composition comprising 0.5 to 30 parts by weight of a (meth) acrylic acid ester polymer or a polymer mixture obtained by polymerization, (C) 0.1 to 30 parts by weight of a filler, and (D) a blowing agent.

Description

Expandable polyester resin composition {EXPANDABLE POLYESTER RESIN COMPOSITION}

Since polyester resins give molded articles having excellent physical properties such as transparency, mechanical properties, gas barrier properties, heat resistance, and chemical properties such as solvent resistance, acid resistance, and alkali resistance, packaging materials such as bottles, sheets, films, and the like It is widely used in various fields. In addition, the foam molding method has recently attracted attention as a means for reducing the weight of polyester resins, improving heat insulation properties, and lowering molded product costs, and there is a strong demand for foamed molded articles having a high magnification of polyester resins in the market.

In foam molding of the said polyester resin, the method of using a branching agent in combination with a foaming agent is generally known.

When carboxylic dianhydride etc. are used as said branching agent, it is known that foaming of high magnification becomes possible by increasing molecular weight increase or melt viscosity of polyester resin in a molten state.

For example, Japanese Patent Nos. 1921348 and 2126744 disclose that the expansion ratio of a foamed molded article can be improved by adding a compound having two or more acid anhydride groups in a molecule such as pyromellitic dianhydride as a branching agent to a polyester resin. Is described.

However, the pyromellitic dianhydride cannot exhibit an effect unless it has a melting point of 280 ° C and a very high temperature and is not heat-molded at a temperature of 270 to 290 ° C. In fact, in the low temperature region of 210 ° C. or less, little effect was found.

The present invention enables a high magnification foam molding even in a low temperature region of 150 ° C to 210 ° C by using a specific (meth) acrylic acid ester polymer without using these branching agents, and is different from these techniques.

In addition, Japanese Laid-Open Patent Publication No. 2000-136301 obtains a foamed molded article having a foaming ratio of 1.6 to 3.0 by adding an acrylic resin to an alloying resin of a polycarbonate and another aromatic ring-containing thermoplastic resin containing a polyester resin. Is described.

The present invention is made by (co) polymerizing a monomer mixture having a specific composition, and at the same time, it is possible to further improve foamability by using a (meth) acrylic acid ester polymer having a specific non-viscosity. Moreover, the fall of the strength of the foamed molded article due to the improvement of the expansion ratio can be improved by adding a filler, which is different from this technique.

The present invention relates to a expandable polyester resin composition. More specifically, the present invention relates to a foamable polyester resin composition which is excellent in workability at low temperature and which gives a high magnification foam molded article excellent in strength and surface properties.

An object of the present invention is to provide a foamed poly that can significantly improve the foaming ratio in foam molding of a polyester resin, and at the same time improve the deterioration of the strength and surface properties of the foamed molded article, which is accompanied by the improvement of the foaming ratio. It is to provide an ester resin composition.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining, the present inventors can improve a foaming ratio significantly by adding a specific (meth) acrylic-ester type polymer, a filler, and a foaming agent to a polyester resin, and can improve the strength and surface property of a foamed molded object. The present inventors have found that a present composition is obtained and have completed the present invention.

That is, this invention is the following structures.

(1) 0 to 49% by weight of at least one monomer selected from 100 parts by weight of (A) polyester resin, (B) 51 to 100% by weight of methyl methacrylate and methacrylic acid ester and acrylate ester except methyl methacrylate And 50 to 100 parts by weight of a monomer mixture (a) consisting of 0 to 20% by weight of a vinyl monomer copolymerizable with these, obtained by emulsion polymerization, and further comprising a solution obtained by dissolving 0.1 g of the polymer in 100 ml of chloroform at 30 ° C. In the presence of a latex of a polymer having a specific viscosity of 0.7 to 1.9, from 0 to 49% by weight of methyl methacrylate, from 51 to 100% by weight of at least one monomer selected from methacrylic acid esters and acrylic acid esters except methyl methacrylate and these 0 to 50 parts by weight of the monomer mixture (b), composed of 0 to 20% by weight of a vinyl monomer copolymerizable with [100 parts by weight in combination with (a) and (b)]. (Meth) acrylic acid ester polymer or polymer, characterized by a polymer or polymer mixture obtained by polymerization, having a specific viscosity of 0.65 to 1.7 at 30 ° C of a solution in which 0.1 g of the polymer or polymer mixture is dissolved in 100 ml of chloroform A foamable polyester resin composition comprising 0.5 to 30 parts by weight of a mixture, (C) 0.1 to 30 parts by weight of a filler, and (D) a blowing agent.

(2) The expandable polyester resin composition according to the above (1), wherein the polyester resin (A) is an amorphous polyester resin.

(3) The expandable polyester resin composition according to the above (1) or (2), wherein the filler (C) is talc, calcium carbonate, mica, wollastonite, clay, or glass fiber.

(4) The foamable polyester resin composition according to any one of the above (1) to (3), wherein the foaming agent (D) is a thermal decomposition type foaming agent, and the amount thereof is 0.1 to 25 parts by weight based on 100 parts by weight of the polyester resin.

(5) A foamed molded article formed by molding the expandable polyester resin composition according to the above (1).

Best Mode for Carrying Out the Invention

It is an object of the present invention to improve the foamability of polyester resins in polymers or polymer mixtures obtained by emulsion polymerization of monomers or monomer mixtures containing a superior amount of specific methacrylic acid esters and / or acrylic acid esters. It is to use as. By using the (meth) acrylic acid ester-based polymer or polymer mixture, blowing agent and filler, it is possible to express the effect of improving the foaming ratio during foam molding without impairing the excellent physical and chemical properties inherent in the polyester resin. have.

The polyester resin used in the present invention is a thermoplastic polyester resin, which is a polymer resin obtained by mixing an aromatic dicarboxylic acid and a dihydric alcohol, that is, a diol, causing an esterification reaction between them, and further polycondensing them. As dicarboxylic acid, dicarboxylic acid containing terephthalic acid or its alkyl ester as a main component is used, and diol containing alkylene glycol as a main component is used as diol.

Although it does not specifically limit as polyester resin used by this invention, The polyester resin and recycled polyester resin which are conventionally used can also be used, An amorphous polyester resin is preferable at the point which is easy to process.

As this amorphous polyester resin, crystallinity is not confirmed substantially or it is low. For example, a homopolymer, a copolymer, or a mixture thereof obtained by polycondensing diol of 50 mol% or more of ethylene glycol and dicarboxylic acids of 50 mol% or more of terephthalic acid or an alkyl ester thereof may be mentioned. For example, copolymers of other dicarboxylic acids such as isophthalic acid or halogenated terephthalic acid in the range of 50 mol% or less of the total carboxylic acids, or poly (alkylene glycol) in the range of 50 mol% or less of the total diol, The thing which copolymerized diethylene glycol or the thing which copolymerized C1-C12 alkylene glycol of an alkyl group, for example, 1, 4- cyclohexane dimethanol, etc. is mentioned.

The (meth) acrylic acid ester polymer or polymer mixture used in the present invention consists of a polymer or polymer mixture obtained by adding and polymerizing a monomer mixture (b) in the presence of a latex of a polymer obtained by emulsion polymerization of the monomer mixture (a). It is a component used for the purpose of improving the foamability of the polyester resin.

The monomer mixture (a) is 50 to 100% methyl methacrylate (wt%, the same below), preferably 51 to 100%, more preferably 60 to 90%, still more preferably 70 to 85%, Copolymerization with 0 to 50%, preferably 0 to 49%, more preferably 0 to 40% and even more preferably 0 to 30% of monomers selected from methacrylic acid esters and acrylic acid esters except for methyl methacrylate Possible vinyl monomers are mixtures consisting of 0 to 20%, preferably 0 to 10%, more preferably 0 to 5%.

When the ratio of methyl methacrylate in the monomer mixture (a) is less than 50%, foamability and processability are lowered. Moreover, when the monomer selected from the methacrylic acid ester and acrylic acid ester except the said methyl methacrylate exceeds 50%, foamability and workability will fall. Moreover, when the vinylic monomer copolymerizable with these exceeds 20%, foamability and workability will fall.

As a specific example of the methacrylic acid ester except the methyl methacrylate in a monomer mixture (a), carbon number of alkyl groups, such as ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, for example Methacrylic acid alkyl ester etc. which are 2-8 are mentioned. Moreover, as an example of acrylate ester, the alkyl acrylate of C1-C8 of alkyl groups, such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate, etc. are mentioned, for example. Methacrylic acid ester and acrylic acid ester except these methyl methacrylates may be used independently, and may be used in combination of 2 or more type.

As a specific example of the vinyl monomer copolymerizable with these in a monomer mixture (a), unsaturated vinyl, such as aromatic vinyl, such as styrene and (alpha) -methylstyrene, and acrylonitrile, etc. are mentioned, for example. These may be used independently and may be used in combination of 2 or more type.

0.1 g of the polymer obtained by emulsion polymerization of the monomer mixture (a) was dissolved in 100 ml of chloroform, and the specific viscosity measured at 30.degree. C. was 0.7 to 1.9, preferably 0.8 to 1.8, more preferably 0.8 to 1.7, particularly Preferably it is 0.9-1.6. When the specific viscosity exceeds 1.9, the foamability and the workability tend to be lowered. If the specific viscosity is less than 0.7, the foamability and the surface property of the foamed molded article tend to be lowered.

The monomer mixture (b) is from 0 to 49% of methyl methacrylate, preferably from 20 to 49%, more preferably from 30 to 45%, selected from methacrylic acid esters and acrylic acid esters except methyl methacrylate. 51 to 100% of the above monomers, preferably 51 to 80%, more preferably 55 to 70%, 0 to 20%, preferably 0 to 10%, more preferably 0 To 5%.

The monomer mixture (b) is polymerized in the presence of a latex of a polymer obtained by polymerizing the monomer mixture (a), and the (meth) acrylic acid ester polymer or polymer is formed by forming a polymer obtained by polymerizing the mixture (b) in an outer layer. When the mixture is added to the polyester resin, viscosity and elasticity can be imparted efficiently to the polyester resin, and as a result, the foamability can be improved.

When the ratio of methyl methacrylate in the monomer mixture (b) exceeds 50%, good foamability and processability tend to be lost. In addition, the case where the ratio of 1 or more types of monomers chosen from methacrylic acid ester and acrylic acid ester except the said methyl methacrylate is less than 50% is the same. In addition, the vinyl monomer copolymerizable with these can be used in the range which does not exceed 20% if needed, but it is preferable that it is as small as possible.

As a specific example of methacrylic acid ester except the methyl methacrylate in a monomer mixture (b), carbon number of alkyl groups, such as ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, is 2, for example. Methacrylic acid alkyl ester etc. which are -8 are mentioned. Moreover, as a specific example of acrylate ester, the alkyl acrylate of C1-C8 of alkyl groups, such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc. are mentioned, for example. Methacrylic acid ester and acrylic acid ester except these methyl methacrylates may be used independently, and may be used in combination of 2 or more type.

As a specific example of the vinyl monomer copolymerizable with these in monomer mixture (b), unsaturated nitriles, such as aromatic vinyl, such as styrene and (alpha) -methylstyrene, and acrylonitrile, etc. are mentioned, for example. These may be used independently and may be used in combination of 2 or more type.

In the presence of the latex of the polymer obtained from the monomer mixture (a), the polymer or polymer mixture obtained by adding and polymerizing the monomer mixture (b) was dissolved at 100 g of chloroform and measured at 30 ° C by dissolving 0.1 g of the polymer or polymer mixture in 100 ml of chloroform. The specific viscosity is 0.1 to 1.7, preferably 0.65 to 1.7, more preferably 0.65 to 1.6, still more preferably 0.7 to 1.5.

When the specific viscosity exceeds 1.7, the foamability and the workability tend to decrease. If the specific viscosity is less than 0.1, the foamability and the surface property of the foamed molded article tend to be lowered.

The ratio of the monomer mixture (a) and the monomer mixture (b) used for producing the (meth) acrylic acid ester polymer or the polymer mixture of the present invention is such that the monomer mixture (a) a) 50 to 100 parts, preferably 60 to 95 parts, more preferably 65 to 90 parts, monomer mixture (b) 0 to 50 parts, preferably 5 to 40 parts, more preferably 10 to 35 parts to be.

If the polymer produced from the monomer mixture (a) is less than about 50 parts, the foamability of the polyester resin cannot be imparted sufficiently. Moreover, when the quantity of the polymer which arises in a monomer mixture (b) exceeds 50 parts, likewise, foaming property of a polyester resin will not be fully provided.

The (meth) acrylic acid ester polymer or the polymer mixture of the present invention can be produced, for example, by the following method. First, the monomer mixture (a) is emulsion polymerized in the presence of a suitable solvent, an emulsifier, a polymerization initiator, a chain transfer agent and the like to obtain a (co) polymer latex from the monomer mixture (a). Next, a monomer mixture (b) is added sequentially and superposition | polymerization is performed. Thus, by sequentially polymerizing each mixture, a single- or two-stage polymer mixture is prepared in which the (co) polymer from the monomer mixture (a) becomes the inner layer and the (co) polymer from the monomer mixture (b) becomes the outer layer. do. The dispersion medium used in the emulsion polymerization is usually water.

As said emulsifier, a well-known thing is used. For example, anionic surfactants such as fatty acid salts, alkyl sulfate ester salts, alkylbenzene sulfonates, alkyl phosphate ester salts, and sulfosuccinic acid diester salts, and nonionic interfaces such as polyoxyethylene alkyl ethers and polyoxyethylene fatty acid esters. Activators and the like.

As said polymerization initiator, water-soluble, oil-soluble polymerization initiator, etc. are used. For example, although inorganic polymerization initiators, such as normal persulfate, or an organic peroxide, an azo compound, etc. can also be used independently, these initiator compounds, a sulfite, thiosulfate, a 1st metal salt, sodium formaldehyde sulfoxylate, etc. are combined, It can also be used as a poison system. Preferred persulfates include, for example, sodium persulfate, potassium persulfate, ammonium persulfate, and the like, and preferred organic peroxides include, for example, t-butylhydroperoxide, cumene hydroperoxide, benzoyl peroxide and lauroyl peroxide. Can be mentioned.

Although there is no limitation in particular as said chain transfer agent, For example, t-dodecyl mercaptan, n-dodecyl mercaptan, t-decyl mercaptan, n-decyl mercaptan, etc. can be used.

There is no restriction | limiting in particular also in the temperature, time, etc. at the time of the said polymerization reaction, According to a use purpose, it can adjust suitably so that it may become desired specific viscosity and particle size.

When the polymerization is carried out by two-stage polymerization, in the addition of the second and subsequent monomers, the polymerization of each stage can be carried out without mixing with the first-stage monomer by confirming and adding that the polymerization in the first stage is completed. Can be.

The particles in the polymer latex thus obtained usually have an average particle diameter of about 100 to 3000 mm 3, and are extracted from the latex by spraying and drying in salting, coagulation or hot air by addition of a normal electrolyte. Moreover, washing | cleaning, dehydration, drying etc. are performed by a conventional method as needed.

It is preferable that the average particle diameter of the (meth) acrylic acid ester type polymer or polymer mixture obtained by the above operation is 30-300 micrometers normally, and is mix | blended with a polyester resin.

The expandable polyester resin composition of this invention is manufactured by mixing the (meth) acrylic acid ester type polymer or polymer mixture of this invention with a polyester resin according to a conventional method.

The addition amount of the (meth) acrylic acid ester polymer or the polymer mixture is 0.5 to 30 parts, preferably 3 to 25 parts, and more preferably 5 to 20 parts with respect to 100 parts of the polyester resin. When the addition amount of the (meth) acrylic acid ester polymer is less than 0.5 part by weight, the effect of adding the (meth) acrylic acid ester polymer is not sufficiently obtained, and when it exceeds 30 parts, the excellent mechanical properties of the polyester resin are impaired.

The blowing agent to be used in the present invention is not particularly limited, but inert gas such as nitrogen gas, carbon dioxide gas, helium, saturated hydrocarbons such as propane, butane, pentane, hexane, halogenated hydrocarbons such as tetrafluoromethane, freon, etc. Physical blowing agents, pyrolytic inorganic blowing agents such as sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, sodium carbonate, ammonium carbonate, N, N'-dinitrosopentamethylenetetraamine, N, N'-dimethyl-N, N'-di Nitroso compounds such as nitrosoterephthalamide, Azo compounds such as azodicarbonamide, azobisisobutyronitrile and barium azodicarboxylate, sulfonylhydrazides such as benzenesulfonyl hydrazide and toluenesulfonylhydrazide Pyrolytic foaming agents, such as thermal decomposition type organic blowing agents such as compounds, are used, but do not use a foam molding facility in which points of foaming efficiency or explosion proof structure are provided. Pyrolytic blowing agents are preferred in that they can be used.

Examples of the thermally decomposed inorganic blowing agent include sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, sodium carbonate, ammonium carbonate and the like. These can be used individually or in mixture of 2 or more types. Especially, sodium bicarbonate is preferable at a foaming efficiency and cost.

Examples of the thermally decomposed organic blowing agent include nitroso compounds such as N, N'-dinitrosopentamethylenetetraamine, N, N'-dimethyl-N, N'-dinitrosoterephthalamide, azodicarbonamide and azobis. Azo compounds, such as isobutyronitrile and a barium azodicarboxylate, sulfonyl hydrazide compounds, such as benzenesulfonyl hydrazide and toluenesulfonyl hydrazide, etc. are mentioned. These can be used individually or in mixture of 2 or more types. Among them, azodicarbonamide is preferred in terms of foaming efficiency and cost.

Although the addition amount of the said blowing agent is not specifically limited according to the objective, Usually, with respect to 100 parts of said polyester resins, Preferably it is 0.1-25 parts, More preferably, it is 0.3-18 parts. When the addition amount of the blowing agent is less than 0.1 part, a molded article having a sufficient foaming ratio is hardly obtained, and when it exceeds 25 parts, a molded molded article of a uniform cell is hard to be obtained.

The addition amount of the blowing agent may be varied in accordance with the addition amount of the (meth) acrylic acid ester polymer or the polymer mixture. For example, in the case of 5 parts of the (meth) acrylic acid ester polymer, the blowing agent is 0.1 based on 100 parts of the polyester resin. In the case of parts, to 5 parts, and 10 parts of the (meth) acrylic acid ester polymer, it is preferable to add 0.5 parts to 10 parts of the blowing agent and 1 to 25 parts of the blowing agent in the case of 20 parts of the (meth) acrylic acid ester polymer.

In order to make the cell of a foamed molded object uniform, and to improve the intensity | strength of a molded object, it is preferable to add a filler to the expandable polyester resin composition of this invention.

Examples of the filler used in the present invention include talc, calcium carbonate, mica, wollastonite, clay, and glass fiber. These can be used individually or in mixture of 2 or more types. Especially, talc, mica, wollastonite, and clay are preferable at the point of strength improvement.

The amount of the filler added is 0.1 to 30 parts, preferably 0.5 to 20 parts, and more preferably 3 to 15 parts with respect to 100 parts of the polyester resin. When the added amount of the filler is less than 0.1 part, a foamed molded article of a uniform cell is not obtained and sufficient strength is hardly obtained. When it exceeds 30 parts, the viscosity at the time of melting increases, and there exists a tendency for the load during shaping | molding to become high.

In the expandable polyester resin composition of the present invention, a compatibilizer for reducing the load of the drive motor of the molding machine in extrusion molding, an electrodeposition agent (electrodeposition agent), a lubricant, and an impact reinforcing agent for preventing the classification of pellets and powders, as necessary. Additives, such as a plasticizer and a coloring agent, can also be added individually or in combination of 2 or more types.

There is no restriction | limiting in particular in the compounding method of the expandable polyester resin composition of this invention. For example, after mixing the polyester resin, (meth) acrylic acid ester-based polymer, thermal decomposition foaming agent, filler and other additives and the like, melt kneading by melt kneading machine such as a single screw twin screw extruder at a temperature suitable for the resin composition, etc. It can manufacture.

The molding method of the expandable polyester resin composition of the present invention is not particularly limited, and a molding method that is generally used, such as an extrusion molding method, may be applied.

Hereinafter, although this invention is demonstrated in detail based on an Example and a comparative example, this invention is not limited to these.

In addition, the evaluation method used by the Example and the comparative example is shown collectively below.

<Measurement of specific viscosity of (meth) acrylic acid ester polymer>

0.1 g of the polymer sample was dissolved in 100 ml of chloroform and measured using a Uberdo-type viscometer maintained at a constant temperature in a 30 ° C water bath.

<Measurement of the expansion ratio>

After measuring the specific gravity of the obtained powder compound (polyester resin composition non-foaming molded body), it shape | molded with CMT-45 by Cincinnati Miracron Co., and obtained specific gravity of the flat plate shaped object (foam molded body of polyester resin composition). The foaming ratio was calculated by the following equation based on the measured value.

Foaming ratio = (specific gravity of polyester resin composition non-foamed molded article) / (specific gravity of foamed molded article of polyester resin composition)

In addition, molding conditions are shown below.

<Molding condition>

Molding temperature: C1 = 150 ° C, C2 = 155 ° C, C3 = 160 ° C, adapter = 170 ° C, dice = 175 ° C

Screw speed: 10 rpm

Discharge amount: 15 kg / hour

Dies: 10 mm × 180 mm

<Measurement of polymerization conversion rate>

The polymerization conversion ratio was calculated by the following equation.

Polymerization Conversion Rate (%) = {Polymer Production / Monomer Injection} × 100

Measurement of Latex Average Particle Size

About the latex of the obtained (meth) acrylic acid ester polymer, the average particle diameter was measured using the light scattering of 546 nm wavelength using the U-2000 spectrophotometer by Hitachi Corporation.

<Evaluation of Surface>

About the surface property of the obtained molded object, external appearance was observed visually and the following references | standards evaluated.

A: The surface unevenness is hardly found and the appearance is excellent.

B: Uneven surface is found, but not very noticeable.

C: A lot of irregularities on the surface are found and the appearance is slightly bad.

D: Uneven surface is bad and appearance is bad.

<Measurement of Compressive Strength>

The compressive strength at the time of 20% compression at 23 degreeC was measured based on JISK7220.

<Measurement of Flexural Strength>

Flexural strength at 23 degreeC was measured based on JISK7221.

<Measurement of Heat Deflection Temperature>

Based on JIS K7207, the heat deflection temperature (hereinafter referred to as HDT) was measured under the condition that the bending stress was 18.5 kgf / cm 2.

Example 1

In an 8-liter reactor with a stirrer, 0.7 parts of sodium dioctylsulfosuccinic acid previously dissolved in water as an emulsifier was added, and then water was added so that the total amount of water was added to 200 parts by adding the quantity contained in the additional raw materials added thereafter. Nitrogen was passed through the gas phase portion and the liquid phase in the reactor to remove oxygen from the space portion and water, and then the contents were heated to 70 ° C. while stirring. Next, a monomer mixture (a) consisting of 60 parts of methyl methacrylate (hereinafter referred to as MMA) and 20 parts of butyl acrylate (hereinafter referred to as BA) was collectively added to the reactor, followed by 0.005 parts of potassium persulfate as an initiator. After addition, the mixture was stirred for 1 hour to substantially complete the polymerization.

Thereafter, the monomer mixture (b) consisting of 6 parts of MMA and 14 parts of BA was added dropwise at a rate of about 30 parts per hour. After completion of the dropwise addition, the contents were kept at 70 ° C for 90 minutes, and then cooled to obtain a polymer latex to measure the average particle diameter. The results are shown in Table 1.

In addition, the polymerization conversion rate at this time was 99.5%. The resulting polymer latex is salted and coagulated with an aqueous calcium chloride solution, heated to 90 ° C., and then filtered using a centrifugal dehydrator. The dehydrated cake of the obtained resin is washed with water equal to the weight of the resin and washed with a parallel flow dryer. It dried on the conditions of 15 degreeC, and the white powdery polymer sample (1) was obtained. In addition, the specific viscosity of the obtained polymer sample (1) was measured. The results are shown in Table 1.

Next, 10 parts of the polymer sample (1), 1.0 part of talc, 5.4 parts of sodium bicarbonate, 0.6 parts of azodicarbonamide, and a compatibilizer (Sumitomo Chemical Co., Ltd.) in 100 parts of polyester resin (Easterman Chemical, EASTER 6763) Foam molded product obtained by blending 1.0 parts of Manufacture, Bond Fast BF-7B) and 0.1 part of Electrodeposition Agent (manufactured by Koshiga Chemical Co., Ltd., polybutene), and pelletizing compound mixed with a Henschel mixer using CMT-45 manufactured by Cincinnati Miracron. The surface properties were evaluated for the foaming ratio. The results are shown in Table 1.

Examples 2 to 7 and Comparative Examples 1 to 3

According to the composition shown in Table 1, the component shown in Table 1 was carried out similarly to Example 1, and the polymer samples (2)-(10) were obtained, respectively, and each characteristic value was measured. In addition, using 10 parts of each of the obtained polymer samples (2) to (10), the mixture was blended with 100 parts of a polyester resin, and foamed molded product was obtained in the same manner as in Example 1, and the above evaluation was carried out to obtain Examples 2 to 7 and It was set as the comparative examples 1-3. The results are shown in Table 1.

Example number One 2 3 4 5 6 7 Comparative Example 1 Comparative Example 2 Comparative Example 3 Polymer sample number (One) (2) (3) (4) (5) (6) (7) (8) (9) 10 The furtherance (part) Monomer mixture (a) MMABMABAEAANSt 60-20 --- 65-10-5- 6510 --- 5 68--12-- 65--510- 70-4--6 75 --- 5- 24-56 --- 32-48 --- 48--12-20 Monomer mixture (b) MMABA 614 614 614 614 614 614 614 614 614 614 Evaluation results Specific viscosity of inner layer polymer 1.11 1.13 1.12 1.12 1.11 1.11 1.06 1.11 1.12 1.03 Specific viscosity of inner and outer polymer mixtures 0.80 0.84 0.80 0.80 0.81 0.82 0.79 0.80 0.82 0.80 Latex average particle diameter 1600 1600 1500 1600 1700 1500 1600 1600 1600 1700 Foam magnification (fold) 5.5 5.4 5.5 5.6 5.4 5.2 4.8 2.8 2.9 2.8 Surface A A A A A A A B B B

From the result of Table 1, when using the (meth) acrylic-ester polymer samples (1)-(7), the composition which has favorable foamability can be obtained, but methacrylic acid ester other than methyl methacrylate, acrylic acid ester, and these Sufficient foamability cannot be obtained when polymer samples (8) to (10) using the monomer mixture (a) equivalents having a higher proportion of copolymerizable vinyl monomers exceeding the scope of the present invention are used. Able to know.

Examples 8-12 and Comparative Examples 4-6

According to the composition shown in Table 2, polymer samples (11) to (18) were obtained in the same manner as in Example 1. The said evaluation was performed using the obtained polymer sample. The results are shown in Table 2.

Example number 8 9 10 11 12 Comparative Example 4 Comparative Example 5 Comparative Example 6 Polymer sample number (11) (12) (13) (14) (15) (16) (17) (18) The furtherance (part) Monomer mixture (a) MMABA 6812 6812 6812 6812 6812 6812 6812 6812 Monomer mixture (b) MMABMABAEAANSt 8210 --- 8282-- 5-13-2- 5-13--2 2-153-- 164 ---- 182 ---- 12 --- 35 Evaluation results Specific viscosity of inner layer polymer 1.12 1.12 1.13 1.13 1.07 1.12 1.13 1.09 Specific viscosity of inner and outer polymer mixture 0.84 0.82 0.83 0.85 0.78 0.80 0.82 0.78 Latex Average Particle Size 1600 1600 1600 1600 1500 1600 1600 1600 Foam magnification (fold) 5.5 5.4 5.5 5.6 5.2 2.8 2.8 2.6 Surface A A A A A B B B

From the results in Table 2, it can be seen that a composition having good foamability can be obtained when the composition of the monomer mixture (b) is in the range of the present invention as in the polymer samples (11) to (15). On the other hand, when the polymer samples (16) to (18) using the monomer mixture (b) equivalents whose composition is outside the scope of the present invention are used, it can be seen that the foamability is lowered.

Examples 13-17 and Comparative Examples 7, 8

According to the composition shown in Table 3, polymer samples (19) to (25) were obtained in the same manner as in Example 1.

The said evaluation was performed about the obtained polymer sample. The results are shown in Table 3.

Example number 13 14 15 16 17 Comparative Example 7 Comparative Example 8 Polymer sample number (19) 20 (21) (22) (23) (24) (25) The furtherance (part) Monomer mixture (a) MMABA 519 6010 6812 7713 8317 328 246 Monomer mixture (b) MMABA 1228 921 614 37 00 1842 2149 Evaluation results Specific viscosity of inner layer polymer 1.23 1.18 1.12 1.06 0.79 1.35 1.42 Specific viscosity of inner and outer polymer mixture 0.80 0.79 0.84 0.82 0.79 0.80 0.82 Latex average particle diameter 1500 1500 1600 1600 1550 1600 1600 Foam magnification (fold) 5.5 5.5 5.6 5.6 6.2 2.9 2.4 Surface A A A A A B B

From the results in Table 3, it can be seen that a composition having good foamability can be obtained when the amount of the monomer mixture (a) is in the range of the present invention as in the polymer samples (19) to (23). On the other hand, it is understood that the foamability is not sufficient when the polymer samples (24) and (25) in which the amount of the monomer mixture (a) is smaller than the range of the present invention are used.

Examples 18-22, 22a and Comparative Examples 9, 10

According to the composition shown in Table 4, polymer samples (26) to (32) and (30a) were obtained in the same manner as in Example 1.

The said evaluation was performed about the obtained polymer sample. The results are shown in Table 4.

Example number 18 19 20 21 22 22a Comparative Example 9 Comparative Example 10 Polymer sample number (26) (27) (28) (29) (30) (30a) (31) (32) The furtherance (part) Monomer mixture (a) MMABA 6812 6812 6812 6812 6812 8515 6812 6812 Monomer mixture (b) MMABA 614 614 614 614 614 - 614 614 Initiator amount (part) 0.02 0.01 0.003 0.001 0.0005 0.007 0.1 0.0001 Emulsifier Volume (part) 0.5 0.7 0.7 0.7 0.7 0.7 0.5 0.7 Evaluation results Specific viscosity of inner layer polymer 0.95 1.01 1.19 1.36 1.68 0.80 0.58 1.92 Specific viscosity of inner and outer polymer mixture 0.65 0.77 0.95 1.16 1.49 0.80 0.27 1.75 Latex Average Particle Size 1550 1500 1650 1650 1600 1550 1600 1600 Foam magnification (part) 4.6 5.5 5.6 8.1 5.2 8.0 2.8 2.9 Surface A A A B B A B B

From the results of Table 4, it can be seen that when the polymer samples 26 to 30 whose specific viscosity are the range of the present invention are used, a composition having good foamability can be obtained. On the other hand, it can be seen that the foamability is not sufficient when the polymer samples 31, 32 having a specific viscosity smaller or larger than the range of the present invention are used.

Examples 23, 24 and Comparative Examples 11-14

In order to evaluate the difference in foamability when the blending quantity with respect to the polyester resin of the polymer sample 28 used in Example 20 was changed, the 100 parts of the polyester resin of the polymer sample 28 used in Example 20 were evaluated. Instead of 10 parts, the number of blended parts was 15 parts or 25 parts, which were shown in Table 5, except that the molded article was obtained in the same manner as in Example 20, and foamability and surface properties were evaluated. The results are shown in Table 5 in comparison with Example 20, denier 10 of the polymer sample. However, in the case of the comparative example 12, the kneading | mixing of the resin composition was not enough, and the molded object suitable for evaluating foamability was not obtained.

Example number 20 23 24 Comparative Example 11 Comparative Example 12 Comparative Example 13 Comparative Example 14 Polymer sample number (28) (28) (28) (28) (28) - - Polymer Sample Copies (Parts) 10 15 25 0.3 40 - - Pyromellitic Acid 2 Anhydride (part) - - - - - 0.4 0.8 Evaluation results Foam magnification (fold) 5.6 6.2 7.2 2.1 - 2.2 2.1 Surface A A A D D B B

In the results of Table 5, the composition in which the polymer sample 28 was blended in the scope of the present invention showed good foamability, but the case of reducing the number of blended parts exceeding the range of the present invention as in Comparative Example 11 and Comparative Examples 13 and 14 In the case where pyromellitic dianhydride is used as described above, it can be seen that sufficient foamability cannot be obtained.

Examples 25-31 and Reference Examples 1, 2

Except having changed the kind and mixing | blending number of foaming agent as Table 6, it carried out similarly to Example 20, the molded object was obtained, and foamability and surface property evaluation were performed. The results are shown in Table 6.

In the table, SBC represents sodium bicarbonate and ADCA represents azodicarbonamide.

Example number 25 26 27 28 20 29 30 31 Reference Example 1 Reference Example 2 Polymer sample number (28) (28) (28) (28) (28) (28) (28) (28) (28) (28) Polymer Sample Copies (Parts) 5 5 5 10 10 20 20 20 5 20 SBC Copies (Parts) 1.5 1.3 2.7 1.8 5.4 5.4 7.2 10.8 0.05 27 ADCA copies (parts) 0 0.2 0.3 0.2 0.6 0.6 0.8 1.2 0 0 Evaluation results Foam magnification (fold) 3.1 3.4 4.4 3.9 5.6 7.2 11.1 3.8 2.2 1.6 Surface A A A A A A A B B D

From the results in Table 6, it can be seen that the composition of the present invention has good foamability.

Examples 32-37 and Comparative Examples 15, 16

Except having changed the kind and mixing | blending number of a filler as shown in Table 7, the molded object was obtained like Example 20, and foamability, surface property, compressive strength, flexural strength, and HDT were evaluated. The results are shown in Table 7.

In addition, the filler in the table used the commercial item as shown below.

Talc: Fuji Talc, LMS-200

Mica: Yamaguchi Unmo Co., Ltd., A-21

Montmorillonite: Sazanclay, CLOISITE-25A

Example number 20 32 33 34 35 36 37 Comparative Example 15 Comparative Example 16 Filler Type talc talc talc mica Montmorillonite Montmorillonite Calcium carbonate talc talc Filler Parts (parts) One 3 15 3 3 3 3 0 35 Evaluation results Foam magnification (fold) 5.6 5.0 5.4 5.6 5.2 5.4 5.4 2.1 3.2 Surface A A A A A A A D D Compressive strength (MPa) 3.3 3.8 4.1 2.6 4.1 4.0 2.2 - - Flexural Strength (MPa) 7.8 9.1 9.5 8.5 10.1 9.5 6.7 - - HDT (℃) 45 50 52 50 53 51 42 - -

In the results of Table 7, the composition in which the various fillers were blended within the scope of the present invention had good foamability, surface properties, compressive strength, flexural strength, and HDT, but the formulation number exceeded the range of the present invention as in Comparative Example 15. In the case of using it with reduced size, since the uniform foaming cell was not obtained, the surface property of the molded body was very bad, and a molded body suitable for performing the above evaluation could not be obtained. In addition, when the compounding quantity was increased beyond the range of the present invention as in Comparative Example 16, the foaming cell was severely broken, and a molded body suitable for the above evaluation could not be obtained.

The expandable polyester resin composition of the present invention can obtain a foamed molded article having a high magnification of about 3 to 15 times by using a polyester resin, a specific (meth) acrylic acid ester polymer, a filler, and a blowing agent, and at the same time, it is produced by the improvement of the expansion ratio. The surface property and the strength of the molded body can be improved. Therefore, it is possible to reduce the manufacturing cost according to the use of the existing extrusion machine, and at the same time the range of use is expanded.

Claims (5)

100 parts by weight of (A) polyester resin, (B) 51 to 100% by weight of methyl methacrylate, 0 to 49% by weight of at least one monomer selected from methacrylic acid ester and acrylate ester except methyl methacrylate, and Specific viscosity at 30 ° C. of a solution obtained by emulsion polymerization of 50 to 100 parts by weight of a monomer mixture (a) consisting of 0 to 20% by weight of a copolymerizable vinyl monomer and dissolving 0.1 g of the polymer in 100 ml of chloroform. In the presence of a latex of 0.7 to 1.9 polymers, from 0 to 49% by weight of methyl methacrylate, from 51 to 100% by weight of at least one monomer selected from methacrylic acid esters and acrylate esters except methyl methacrylate and copolymerizable with these 0 to 50 parts by weight of the monomer mixture (b) consisting of 0 to 20% by weight of a vinyl monomer [100 parts by weight in combination with (a) and (Meth) acrylic acid ester polymer or polymer mixture, wherein the specific viscosity at 30 ° C of the solution obtained by dissolving 0.1 g of the polymer or polymer mixture in 100 ml of chloroform is 0.65 to 1.7. A foamable polyester resin composition comprising 0.5 to 30 parts by weight, (C) filler of 0.1 to 30 parts by weight, and (D) a blowing agent. The expandable polyester resin composition according to claim 1, wherein the polyester resin (A) is an amorphous polyester resin. The expandable polyester resin composition according to claim 1 or 2, wherein the filler (C) is talc, calcium carbonate, mica, wollastonite, clay or glass fibers. The expandable polyester resin composition according to any one of claims 1 to 3, wherein the blowing agent (D) is a thermal decomposition type blowing agent, and the amount thereof is 0.1 to 25 parts by weight based on 100 parts by weight of the polyester resin. A foamed molded article formed by molding the expandable polyester resin composition according to claim 1.